linux/drivers/mtd/mtdpart.c
Mike Dunn edbc4540e0 mtd: driver _read() returns max_bitflips; mtd_read() returns -EUCLEAN
The drivers' _read() method, absent an error, returns a non-negative integer
indicating the maximum number of bit errors that were corrected in any one
region comprising an ecc step.  MTD returns -EUCLEAN if this is >=
bitflip_threshold, 0 otherwise.  If bitflip_threshold is zero, the comparison is
not made since these devices lack ECC and always return zero in the non-error
case (thanks Brian)¹.  Note that this is a subtle change to the driver
interface.

This and the preceding patches in this set were tested with ubi on top of the
nandsim and docg4 devices, running the ubi test io_basic from mtd-utils.

¹ http://lists.infradead.org/pipermail/linux-mtd/2012-March/040468.html

Signed-off-by: Mike Dunn <mikedunn@newsguy.com>
Acked-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Brian Norris <computersforpeace@gmail.com>
Ivan Djelic <ivan.djelic@parrot.com>
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com>

Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>
2012-05-13 23:14:23 -05:00

762 lines
20 KiB
C

/*
* Simple MTD partitioning layer
*
* Copyright © 2000 Nicolas Pitre <nico@fluxnic.net>
* Copyright © 2002 Thomas Gleixner <gleixner@linutronix.de>
* Copyright © 2000-2010 David Woodhouse <dwmw2@infradead.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/list.h>
#include <linux/kmod.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/partitions.h>
#include <linux/err.h>
#include "mtdcore.h"
/* Our partition linked list */
static LIST_HEAD(mtd_partitions);
static DEFINE_MUTEX(mtd_partitions_mutex);
/* Our partition node structure */
struct mtd_part {
struct mtd_info mtd;
struct mtd_info *master;
uint64_t offset;
struct list_head list;
};
/*
* Given a pointer to the MTD object in the mtd_part structure, we can retrieve
* the pointer to that structure with this macro.
*/
#define PART(x) ((struct mtd_part *)(x))
/*
* MTD methods which simply translate the effective address and pass through
* to the _real_ device.
*/
static int part_read(struct mtd_info *mtd, loff_t from, size_t len,
size_t *retlen, u_char *buf)
{
struct mtd_part *part = PART(mtd);
struct mtd_ecc_stats stats;
int res;
stats = part->master->ecc_stats;
res = part->master->_read(part->master, from + part->offset, len,
retlen, buf);
if (unlikely(mtd_is_eccerr(res)))
mtd->ecc_stats.failed +=
part->master->ecc_stats.failed - stats.failed;
else
mtd->ecc_stats.corrected +=
part->master->ecc_stats.corrected - stats.corrected;
return res;
}
static int part_point(struct mtd_info *mtd, loff_t from, size_t len,
size_t *retlen, void **virt, resource_size_t *phys)
{
struct mtd_part *part = PART(mtd);
return part->master->_point(part->master, from + part->offset, len,
retlen, virt, phys);
}
static int part_unpoint(struct mtd_info *mtd, loff_t from, size_t len)
{
struct mtd_part *part = PART(mtd);
return part->master->_unpoint(part->master, from + part->offset, len);
}
static unsigned long part_get_unmapped_area(struct mtd_info *mtd,
unsigned long len,
unsigned long offset,
unsigned long flags)
{
struct mtd_part *part = PART(mtd);
offset += part->offset;
return part->master->_get_unmapped_area(part->master, len, offset,
flags);
}
static int part_read_oob(struct mtd_info *mtd, loff_t from,
struct mtd_oob_ops *ops)
{
struct mtd_part *part = PART(mtd);
int res;
if (from >= mtd->size)
return -EINVAL;
if (ops->datbuf && from + ops->len > mtd->size)
return -EINVAL;
/*
* If OOB is also requested, make sure that we do not read past the end
* of this partition.
*/
if (ops->oobbuf) {
size_t len, pages;
if (ops->mode == MTD_OPS_AUTO_OOB)
len = mtd->oobavail;
else
len = mtd->oobsize;
pages = mtd_div_by_ws(mtd->size, mtd);
pages -= mtd_div_by_ws(from, mtd);
if (ops->ooboffs + ops->ooblen > pages * len)
return -EINVAL;
}
res = part->master->_read_oob(part->master, from + part->offset, ops);
if (unlikely(res)) {
if (mtd_is_bitflip(res))
mtd->ecc_stats.corrected++;
if (mtd_is_eccerr(res))
mtd->ecc_stats.failed++;
}
return res;
}
static int part_read_user_prot_reg(struct mtd_info *mtd, loff_t from,
size_t len, size_t *retlen, u_char *buf)
{
struct mtd_part *part = PART(mtd);
return part->master->_read_user_prot_reg(part->master, from, len,
retlen, buf);
}
static int part_get_user_prot_info(struct mtd_info *mtd,
struct otp_info *buf, size_t len)
{
struct mtd_part *part = PART(mtd);
return part->master->_get_user_prot_info(part->master, buf, len);
}
static int part_read_fact_prot_reg(struct mtd_info *mtd, loff_t from,
size_t len, size_t *retlen, u_char *buf)
{
struct mtd_part *part = PART(mtd);
return part->master->_read_fact_prot_reg(part->master, from, len,
retlen, buf);
}
static int part_get_fact_prot_info(struct mtd_info *mtd, struct otp_info *buf,
size_t len)
{
struct mtd_part *part = PART(mtd);
return part->master->_get_fact_prot_info(part->master, buf, len);
}
static int part_write(struct mtd_info *mtd, loff_t to, size_t len,
size_t *retlen, const u_char *buf)
{
struct mtd_part *part = PART(mtd);
return part->master->_write(part->master, to + part->offset, len,
retlen, buf);
}
static int part_panic_write(struct mtd_info *mtd, loff_t to, size_t len,
size_t *retlen, const u_char *buf)
{
struct mtd_part *part = PART(mtd);
return part->master->_panic_write(part->master, to + part->offset, len,
retlen, buf);
}
static int part_write_oob(struct mtd_info *mtd, loff_t to,
struct mtd_oob_ops *ops)
{
struct mtd_part *part = PART(mtd);
if (to >= mtd->size)
return -EINVAL;
if (ops->datbuf && to + ops->len > mtd->size)
return -EINVAL;
return part->master->_write_oob(part->master, to + part->offset, ops);
}
static int part_write_user_prot_reg(struct mtd_info *mtd, loff_t from,
size_t len, size_t *retlen, u_char *buf)
{
struct mtd_part *part = PART(mtd);
return part->master->_write_user_prot_reg(part->master, from, len,
retlen, buf);
}
static int part_lock_user_prot_reg(struct mtd_info *mtd, loff_t from,
size_t len)
{
struct mtd_part *part = PART(mtd);
return part->master->_lock_user_prot_reg(part->master, from, len);
}
static int part_writev(struct mtd_info *mtd, const struct kvec *vecs,
unsigned long count, loff_t to, size_t *retlen)
{
struct mtd_part *part = PART(mtd);
return part->master->_writev(part->master, vecs, count,
to + part->offset, retlen);
}
static int part_erase(struct mtd_info *mtd, struct erase_info *instr)
{
struct mtd_part *part = PART(mtd);
int ret;
instr->addr += part->offset;
ret = part->master->_erase(part->master, instr);
if (ret) {
if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
instr->fail_addr -= part->offset;
instr->addr -= part->offset;
}
return ret;
}
void mtd_erase_callback(struct erase_info *instr)
{
if (instr->mtd->_erase == part_erase) {
struct mtd_part *part = PART(instr->mtd);
if (instr->fail_addr != MTD_FAIL_ADDR_UNKNOWN)
instr->fail_addr -= part->offset;
instr->addr -= part->offset;
}
if (instr->callback)
instr->callback(instr);
}
EXPORT_SYMBOL_GPL(mtd_erase_callback);
static int part_lock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
struct mtd_part *part = PART(mtd);
return part->master->_lock(part->master, ofs + part->offset, len);
}
static int part_unlock(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
struct mtd_part *part = PART(mtd);
return part->master->_unlock(part->master, ofs + part->offset, len);
}
static int part_is_locked(struct mtd_info *mtd, loff_t ofs, uint64_t len)
{
struct mtd_part *part = PART(mtd);
return part->master->_is_locked(part->master, ofs + part->offset, len);
}
static void part_sync(struct mtd_info *mtd)
{
struct mtd_part *part = PART(mtd);
part->master->_sync(part->master);
}
static int part_suspend(struct mtd_info *mtd)
{
struct mtd_part *part = PART(mtd);
return part->master->_suspend(part->master);
}
static void part_resume(struct mtd_info *mtd)
{
struct mtd_part *part = PART(mtd);
part->master->_resume(part->master);
}
static int part_block_isbad(struct mtd_info *mtd, loff_t ofs)
{
struct mtd_part *part = PART(mtd);
ofs += part->offset;
return part->master->_block_isbad(part->master, ofs);
}
static int part_block_markbad(struct mtd_info *mtd, loff_t ofs)
{
struct mtd_part *part = PART(mtd);
int res;
ofs += part->offset;
res = part->master->_block_markbad(part->master, ofs);
if (!res)
mtd->ecc_stats.badblocks++;
return res;
}
static inline void free_partition(struct mtd_part *p)
{
kfree(p->mtd.name);
kfree(p);
}
/*
* This function unregisters and destroy all slave MTD objects which are
* attached to the given master MTD object.
*/
int del_mtd_partitions(struct mtd_info *master)
{
struct mtd_part *slave, *next;
int ret, err = 0;
mutex_lock(&mtd_partitions_mutex);
list_for_each_entry_safe(slave, next, &mtd_partitions, list)
if (slave->master == master) {
ret = del_mtd_device(&slave->mtd);
if (ret < 0) {
err = ret;
continue;
}
list_del(&slave->list);
free_partition(slave);
}
mutex_unlock(&mtd_partitions_mutex);
return err;
}
static struct mtd_part *allocate_partition(struct mtd_info *master,
const struct mtd_partition *part, int partno,
uint64_t cur_offset)
{
struct mtd_part *slave;
char *name;
/* allocate the partition structure */
slave = kzalloc(sizeof(*slave), GFP_KERNEL);
name = kstrdup(part->name, GFP_KERNEL);
if (!name || !slave) {
printk(KERN_ERR"memory allocation error while creating partitions for \"%s\"\n",
master->name);
kfree(name);
kfree(slave);
return ERR_PTR(-ENOMEM);
}
/* set up the MTD object for this partition */
slave->mtd.type = master->type;
slave->mtd.flags = master->flags & ~part->mask_flags;
slave->mtd.size = part->size;
slave->mtd.writesize = master->writesize;
slave->mtd.writebufsize = master->writebufsize;
slave->mtd.oobsize = master->oobsize;
slave->mtd.oobavail = master->oobavail;
slave->mtd.subpage_sft = master->subpage_sft;
slave->mtd.name = name;
slave->mtd.owner = master->owner;
slave->mtd.backing_dev_info = master->backing_dev_info;
/* NOTE: we don't arrange MTDs as a tree; it'd be error-prone
* to have the same data be in two different partitions.
*/
slave->mtd.dev.parent = master->dev.parent;
slave->mtd._read = part_read;
slave->mtd._write = part_write;
if (master->_panic_write)
slave->mtd._panic_write = part_panic_write;
if (master->_point && master->_unpoint) {
slave->mtd._point = part_point;
slave->mtd._unpoint = part_unpoint;
}
if (master->_get_unmapped_area)
slave->mtd._get_unmapped_area = part_get_unmapped_area;
if (master->_read_oob)
slave->mtd._read_oob = part_read_oob;
if (master->_write_oob)
slave->mtd._write_oob = part_write_oob;
if (master->_read_user_prot_reg)
slave->mtd._read_user_prot_reg = part_read_user_prot_reg;
if (master->_read_fact_prot_reg)
slave->mtd._read_fact_prot_reg = part_read_fact_prot_reg;
if (master->_write_user_prot_reg)
slave->mtd._write_user_prot_reg = part_write_user_prot_reg;
if (master->_lock_user_prot_reg)
slave->mtd._lock_user_prot_reg = part_lock_user_prot_reg;
if (master->_get_user_prot_info)
slave->mtd._get_user_prot_info = part_get_user_prot_info;
if (master->_get_fact_prot_info)
slave->mtd._get_fact_prot_info = part_get_fact_prot_info;
if (master->_sync)
slave->mtd._sync = part_sync;
if (!partno && !master->dev.class && master->_suspend &&
master->_resume) {
slave->mtd._suspend = part_suspend;
slave->mtd._resume = part_resume;
}
if (master->_writev)
slave->mtd._writev = part_writev;
if (master->_lock)
slave->mtd._lock = part_lock;
if (master->_unlock)
slave->mtd._unlock = part_unlock;
if (master->_is_locked)
slave->mtd._is_locked = part_is_locked;
if (master->_block_isbad)
slave->mtd._block_isbad = part_block_isbad;
if (master->_block_markbad)
slave->mtd._block_markbad = part_block_markbad;
slave->mtd._erase = part_erase;
slave->master = master;
slave->offset = part->offset;
if (slave->offset == MTDPART_OFS_APPEND)
slave->offset = cur_offset;
if (slave->offset == MTDPART_OFS_NXTBLK) {
slave->offset = cur_offset;
if (mtd_mod_by_eb(cur_offset, master) != 0) {
/* Round up to next erasesize */
slave->offset = (mtd_div_by_eb(cur_offset, master) + 1) * master->erasesize;
printk(KERN_NOTICE "Moving partition %d: "
"0x%012llx -> 0x%012llx\n", partno,
(unsigned long long)cur_offset, (unsigned long long)slave->offset);
}
}
if (slave->offset == MTDPART_OFS_RETAIN) {
slave->offset = cur_offset;
if (master->size - slave->offset >= slave->mtd.size) {
slave->mtd.size = master->size - slave->offset
- slave->mtd.size;
} else {
printk(KERN_ERR "mtd partition \"%s\" doesn't have enough space: %#llx < %#llx, disabled\n",
part->name, master->size - slave->offset,
slave->mtd.size);
/* register to preserve ordering */
goto out_register;
}
}
if (slave->mtd.size == MTDPART_SIZ_FULL)
slave->mtd.size = master->size - slave->offset;
printk(KERN_NOTICE "0x%012llx-0x%012llx : \"%s\"\n", (unsigned long long)slave->offset,
(unsigned long long)(slave->offset + slave->mtd.size), slave->mtd.name);
/* let's do some sanity checks */
if (slave->offset >= master->size) {
/* let's register it anyway to preserve ordering */
slave->offset = 0;
slave->mtd.size = 0;
printk(KERN_ERR"mtd: partition \"%s\" is out of reach -- disabled\n",
part->name);
goto out_register;
}
if (slave->offset + slave->mtd.size > master->size) {
slave->mtd.size = master->size - slave->offset;
printk(KERN_WARNING"mtd: partition \"%s\" extends beyond the end of device \"%s\" -- size truncated to %#llx\n",
part->name, master->name, (unsigned long long)slave->mtd.size);
}
if (master->numeraseregions > 1) {
/* Deal with variable erase size stuff */
int i, max = master->numeraseregions;
u64 end = slave->offset + slave->mtd.size;
struct mtd_erase_region_info *regions = master->eraseregions;
/* Find the first erase regions which is part of this
* partition. */
for (i = 0; i < max && regions[i].offset <= slave->offset; i++)
;
/* The loop searched for the region _behind_ the first one */
if (i > 0)
i--;
/* Pick biggest erasesize */
for (; i < max && regions[i].offset < end; i++) {
if (slave->mtd.erasesize < regions[i].erasesize) {
slave->mtd.erasesize = regions[i].erasesize;
}
}
BUG_ON(slave->mtd.erasesize == 0);
} else {
/* Single erase size */
slave->mtd.erasesize = master->erasesize;
}
if ((slave->mtd.flags & MTD_WRITEABLE) &&
mtd_mod_by_eb(slave->offset, &slave->mtd)) {
/* Doesn't start on a boundary of major erase size */
/* FIXME: Let it be writable if it is on a boundary of
* _minor_ erase size though */
slave->mtd.flags &= ~MTD_WRITEABLE;
printk(KERN_WARNING"mtd: partition \"%s\" doesn't start on an erase block boundary -- force read-only\n",
part->name);
}
if ((slave->mtd.flags & MTD_WRITEABLE) &&
mtd_mod_by_eb(slave->mtd.size, &slave->mtd)) {
slave->mtd.flags &= ~MTD_WRITEABLE;
printk(KERN_WARNING"mtd: partition \"%s\" doesn't end on an erase block -- force read-only\n",
part->name);
}
slave->mtd.ecclayout = master->ecclayout;
slave->mtd.ecc_strength = master->ecc_strength;
slave->mtd.bitflip_threshold = master->bitflip_threshold;
if (master->_block_isbad) {
uint64_t offs = 0;
while (offs < slave->mtd.size) {
if (mtd_block_isbad(master, offs + slave->offset))
slave->mtd.ecc_stats.badblocks++;
offs += slave->mtd.erasesize;
}
}
out_register:
return slave;
}
int mtd_add_partition(struct mtd_info *master, char *name,
long long offset, long long length)
{
struct mtd_partition part;
struct mtd_part *p, *new;
uint64_t start, end;
int ret = 0;
/* the direct offset is expected */
if (offset == MTDPART_OFS_APPEND ||
offset == MTDPART_OFS_NXTBLK)
return -EINVAL;
if (length == MTDPART_SIZ_FULL)
length = master->size - offset;
if (length <= 0)
return -EINVAL;
part.name = name;
part.size = length;
part.offset = offset;
part.mask_flags = 0;
part.ecclayout = NULL;
new = allocate_partition(master, &part, -1, offset);
if (IS_ERR(new))
return PTR_ERR(new);
start = offset;
end = offset + length;
mutex_lock(&mtd_partitions_mutex);
list_for_each_entry(p, &mtd_partitions, list)
if (p->master == master) {
if ((start >= p->offset) &&
(start < (p->offset + p->mtd.size)))
goto err_inv;
if ((end >= p->offset) &&
(end < (p->offset + p->mtd.size)))
goto err_inv;
}
list_add(&new->list, &mtd_partitions);
mutex_unlock(&mtd_partitions_mutex);
add_mtd_device(&new->mtd);
return ret;
err_inv:
mutex_unlock(&mtd_partitions_mutex);
free_partition(new);
return -EINVAL;
}
EXPORT_SYMBOL_GPL(mtd_add_partition);
int mtd_del_partition(struct mtd_info *master, int partno)
{
struct mtd_part *slave, *next;
int ret = -EINVAL;
mutex_lock(&mtd_partitions_mutex);
list_for_each_entry_safe(slave, next, &mtd_partitions, list)
if ((slave->master == master) &&
(slave->mtd.index == partno)) {
ret = del_mtd_device(&slave->mtd);
if (ret < 0)
break;
list_del(&slave->list);
free_partition(slave);
break;
}
mutex_unlock(&mtd_partitions_mutex);
return ret;
}
EXPORT_SYMBOL_GPL(mtd_del_partition);
/*
* This function, given a master MTD object and a partition table, creates
* and registers slave MTD objects which are bound to the master according to
* the partition definitions.
*
* We don't register the master, or expect the caller to have done so,
* for reasons of data integrity.
*/
int add_mtd_partitions(struct mtd_info *master,
const struct mtd_partition *parts,
int nbparts)
{
struct mtd_part *slave;
uint64_t cur_offset = 0;
int i;
printk(KERN_NOTICE "Creating %d MTD partitions on \"%s\":\n", nbparts, master->name);
for (i = 0; i < nbparts; i++) {
slave = allocate_partition(master, parts + i, i, cur_offset);
if (IS_ERR(slave))
return PTR_ERR(slave);
mutex_lock(&mtd_partitions_mutex);
list_add(&slave->list, &mtd_partitions);
mutex_unlock(&mtd_partitions_mutex);
add_mtd_device(&slave->mtd);
cur_offset = slave->offset + slave->mtd.size;
}
return 0;
}
static DEFINE_SPINLOCK(part_parser_lock);
static LIST_HEAD(part_parsers);
static struct mtd_part_parser *get_partition_parser(const char *name)
{
struct mtd_part_parser *p, *ret = NULL;
spin_lock(&part_parser_lock);
list_for_each_entry(p, &part_parsers, list)
if (!strcmp(p->name, name) && try_module_get(p->owner)) {
ret = p;
break;
}
spin_unlock(&part_parser_lock);
return ret;
}
#define put_partition_parser(p) do { module_put((p)->owner); } while (0)
int register_mtd_parser(struct mtd_part_parser *p)
{
spin_lock(&part_parser_lock);
list_add(&p->list, &part_parsers);
spin_unlock(&part_parser_lock);
return 0;
}
EXPORT_SYMBOL_GPL(register_mtd_parser);
int deregister_mtd_parser(struct mtd_part_parser *p)
{
spin_lock(&part_parser_lock);
list_del(&p->list);
spin_unlock(&part_parser_lock);
return 0;
}
EXPORT_SYMBOL_GPL(deregister_mtd_parser);
/*
* Do not forget to update 'parse_mtd_partitions()' kerneldoc comment if you
* are changing this array!
*/
static const char *default_mtd_part_types[] = {
"cmdlinepart",
"ofpart",
NULL
};
/**
* parse_mtd_partitions - parse MTD partitions
* @master: the master partition (describes whole MTD device)
* @types: names of partition parsers to try or %NULL
* @pparts: array of partitions found is returned here
* @data: MTD partition parser-specific data
*
* This function tries to find partition on MTD device @master. It uses MTD
* partition parsers, specified in @types. However, if @types is %NULL, then
* the default list of parsers is used. The default list contains only the
* "cmdlinepart" and "ofpart" parsers ATM.
*
* This function may return:
* o a negative error code in case of failure
* o zero if no partitions were found
* o a positive number of found partitions, in which case on exit @pparts will
* point to an array containing this number of &struct mtd_info objects.
*/
int parse_mtd_partitions(struct mtd_info *master, const char **types,
struct mtd_partition **pparts,
struct mtd_part_parser_data *data)
{
struct mtd_part_parser *parser;
int ret = 0;
if (!types)
types = default_mtd_part_types;
for ( ; ret <= 0 && *types; types++) {
parser = get_partition_parser(*types);
if (!parser && !request_module("%s", *types))
parser = get_partition_parser(*types);
if (!parser)
continue;
ret = (*parser->parse_fn)(master, pparts, data);
if (ret > 0) {
printk(KERN_NOTICE "%d %s partitions found on MTD device %s\n",
ret, parser->name, master->name);
}
put_partition_parser(parser);
}
return ret;
}
int mtd_is_partition(struct mtd_info *mtd)
{
struct mtd_part *part;
int ispart = 0;
mutex_lock(&mtd_partitions_mutex);
list_for_each_entry(part, &mtd_partitions, list)
if (&part->mtd == mtd) {
ispart = 1;
break;
}
mutex_unlock(&mtd_partitions_mutex);
return ispart;
}
EXPORT_SYMBOL_GPL(mtd_is_partition);